For Grade 4 Students (Ages 9-10) - Let's learn to measure length and convert units!
We use different units to measure the length of things. In this lesson, you will learn to:
We use centimeters to measure the length of small things. For example, the length of a pencil, the width of a book. We measure centimeters using a ruler or a measuring tape.
Example:
The length of a pencil can be 15 cm.
The width of an exercise book can be 20 cm.
We use meters to measure the length of large things. For example, the length of a room, the height of a tree. The relationship between meters and centimeters is:
1 m = 100 cm
Example:
The length of a classroom can be 8 m.
The length of a playground can be 50 m.
To convert meters to centimeters, multiply the number of meters by 100.
Example: Convert 3 m to centimeters
To convert centimeters to meters and centimeters, divide the number of centimeters by 100. The whole number obtained will be meters, and the remainder will be centimeters.
Example: Convert 370 cm to meters and centimeters
When adding lengths, add centimeters with centimeters and meters with meters. If the sum of centimeters is 100 or more, carry over 1 m for every 100 cm to the meters place.
Example: 5 m 25 cm + 3 m 70 cm
Example 2: 4 m 80 cm + 2 m 50 cm
($80 + 50 = 130$ cm. $130$ cm is $1$ m $30$ cm. Carry over $1$ m to the meters place.)
When subtracting lengths, subtract centimeters from centimeters and meters from meters. If there are not enough centimeters to subtract from, borrow 1 m (which is 100 cm) from the meters place.
Example: 8 m 50 cm - 3 m 30 cm
Example 2: 10 m 27 cm - 4 m 56 cm
(Since 56 cm cannot be subtracted from 27 cm, borrow 1 m (i.e., 100 cm) from 10 m. $27 + 100 = 127$ cm.)
Convert the following meters to centimeters and enter the answer.
Convert the following centimeters to meters and centimeters and enter the answer.
Add the following lengths and enter the answer.
Subtract the following lengths and enter the answer.